I think your missing the point DER are not the enemy or anything...

I think your missing the point DER are not the enemy or anything else, they have a standard and guidelines that are required to be met.
They would have told PLS where they went wrong and what is required to meet those standards.
If the analysis of the samples didn't meet those requirements PLS wouldn't have bothered to resubmit, most gov agencies are pretty good and helpful if you need permits. In your post it sounds like pls have to keep guessing but I am sure like most agencies it's pretty black and white, any environmental consultant would've after consultation with DER knew what was needed and made adjustments to there work to come in with the framework.
I really don't understand the knifes edge comment as it either passes or doesn't maybe the first effort maybe put down to misinterpretation ,But really after being told again what is required you would expect any company to meet it before resubmission. I am sure they would've taken advice though der that they met guidelines before resubmitting. I am sure a few out there have had to deal with Government agencies and permits and know you can get advice before submitting or resubmitting to make sure that there ok and will pass.

Opps make that Nagrom submitting permits.